Split key.



C. J. WYMER.

SPLIT KEY.

APPLICATEON FILED OCT. 29. 1914.

Patented Nov. 16, 1915.

CHARLES J. WYMER, OF CHICAGO, ILLINOIS.

SPLIT KEY.

Specification of Letters Patent.

Patented Nov. 16, 1915.

Application filed October 29, 1914. Serial No. 869,169.

To all whom it may concern:

Be it known that 1, CHARLES J. WYMER,

a citizen of the United States, and a residentof.;Qhicago, in the State of Illinois, have in- Vented certain new and useful Improvements in Split Keys, of which the following is a specification.

My present invention relates to cotter pins and is designed more particularly to provide a construction which shall ofier the maximum resistance to accidental removal.

The principal objects of my present invention are to provide a cotter pin which shall offer the maximum resistance to accidental removal; to provide a cotter pin having a plurality. of projecting parts on each arm of the pin adapted to contact successively with the edges of the hole in which the cotter pin is arranged; to provide a cotter pin which can be inserted'into its hole with the maximum of ease, and generally to improve, simplify and cheapen the construction of cotter pins.

In attaining the foregoing objects and certain other advantages to be hereinafter described I have provided the construction illustrated in the accompanying drawings, wherein Figure 1 is a section through a bolt show ing my improved cotter pin in position; Fig. 2 is a similar view to Fig. 1 except that the pin is shown in the process of insertion; Fig. 3 is a section on the line 33 of Fig. 2 looking in ,the direction of the arrows; Fig. 4: is a view similar to that shown in Fig. 1 of another form of my improved cotter pin; Fig. 5 is a further View of the form of cotter pin shown in Fig. 1, showing the pin in the process of insertion; and Fig. 6 is a section on the line 6-6 of Fig. 4 looking in the direction of the arrows.

Referring to Figs. 1 to 30f the drawings .it will be seen that the pin consistsof two arms 10 connected by a rounded end 9 which acts in known manner as a spring connection between two arms 10. These two arms 10 are provided with outwardly curved projecting parts 11 formed by bending in a suitable manner the metal of the arms. These outwardly curved projecting parts are preferably arranged at such a distance from the rounded end 9 that when thecotter is in position there is little or no free-longitudinal movement of the pin in its 'hole."

The arms of the pin are preferably not-cut off-short at theend of the outwardly. curved parts 11, but provided instead With straight normally diverging tips 12. The main object of these tips is to aid in the insertion of the cotter pinwithin its hole 13 in the bolt 14. Before discussing the action of these tips 12 it should be pointed out that the outwardly curved parts are preferably made to extend outwardly to such an extent that a pivotal springing movement of the arms 10 about the spring end 9, suflicient to bring the arms into contact, is not suiiicient to allow these curved parts 11 to pass throughthe hole 13. Accordingly, temporary deformation ofthe parts 11 must also take place as illustrated in Fig. 2. Obviously, this deformation of parts 11 requires considerableforce so that as a general rule the cotter pin has to be hammered through the hole.

It is evident that the cotter pin must be held in someway while it is being hammered into its hole and it is to provide such holding means that the tips 12 are provided, for if the arms of the cotter pin were cut ofl at the end of the rounded parts 11 the pin as a whole would have a wedge-shaped end so that it wouldbe necessary to hold the pin by hand with its ends compressed, over the edge of the hole while the rounded end 9 was hammered to force the parts 11' eration is removed. This preliminaryengagement is made possible by forming these tips so that even when pressed together they either diverge or are at least parallel so that the outer parts of these tips will be in contact with the inner parts of the hole 13 and i not merely the outer edge of the hole thereby avoiding any wedging action which would result in the pin umpingback out of its hole as soon as the hand or other restraining means were removed. The pin' with its tips so arranged in the hole 13 can then be driven home without further trouble.

Not only does the provision of tips 12 enable the cotter pin to be placed in a temporary holding position in its hole prior to being driven home, but it also provides further means than the parts 11 for preventing the accidental removal of the pin. For this purpose the tips 12 and the adjacent outwardly curved parts 11 can be so formed that-if the pin is driven rearwardly out of the hole 13 the diverging tips 12 will contact with the edges of the hole 13 before the widest part of the projecting portions 11 have moved out of the hole 13. \Vhen this position is reached the tips 12 will have to be sprung inwardly before the curved parts 11 spring outwardly again and thereby allow the tips 12 to assume their normal position relative to the other parts of the arms 10.

With the form of cotter just described and illustrated in Figs. 1 to 3 it will be evident that the question as to whether or not the pin is removed by an accidental blow on the tips 12 depends entirely on whether the blow vis sufliciently strong to compress the arm together, then deform the parts 11 and subsequently the tips 12. Accordingly, with a view to providing a cotter pin which would require a much stronger blow than that required to deform the parts before it could be accidentally removed I have provided the construction illustrated in Figs. 4 to 6. In thiscase actual shearing of a part of the pin or else a part of the bolt in which the pin is arranged must take place before a straight blow on the tips will remove the pin. This result is accomplished by providing shoulders 15 adjacent the outwardly bent parts of the pin 11 which shoulders provide direct opposition to accidental removal. It will be evident that a straight blow at the end ofthe cotter pin cannot drive the latter out of the hole 13 unless these shoulders 15 are sheared OK or unless these shoulders cut grooves along the sides of the hole 13 in the bolt 14.

Although it is desirable to make it pracother the shoulders 15 can be readily slipped inside the hole 13 whereupon the cotter pin can be removed by striking a blow on the tips 12. It will be evident that if it was necessary to deform the parts 11 before the shoulders 15 could be brought out of engagement with the edges of the hole 13 the pin would be practically non-removable.

If the shoulders 15 were relied on as the sole means of preventing accidental removal of the pin it might happen that the ends of the pin might be pressed together in such a way that the shoulders 15 were slipped inside the edges of the hole 13, in which case no further resistance to removal would be encountered. It is quite possible that this might happen, especially in view of the fact that the springing together of the arms 10 does not require a great deal of force. Ascordingly, I prefer to employ in addition to the shoulders 15 the outwardly curved parts 11 which act as an additional safeguard against accidental removal, particularly, since the deformation of the outwardly curved parts '11 requires the expenditure of much greater force than that required to spring together the arms 10. This arrangement has the further advantage that the shoulders provide ample protection against a straight blow on the ends of the tips 12, while the outwardly curved parts 11 provide further protection in case the shoulders 15 have been sprung inside the hole 13 by oblique blows.

Having thus described my invention and illustrated its use what I claim as new and desire to secure by Letters Patent is 1. A cotter pin having a plurality of projecting portions adapted to engage successively with the edges of thehole in which the pin is located.

2. A cotter pin having rearwardly projecting shoulders adapted to engage the edges of the hole in which the pin is located, and end portions extending outwardly and then inwardly beyond said shoulders.

3. A cotter pin having rearwardly projecting shoulders adapted to engage the edge of a hole in a bolt, end portions extending outwardly and then inwardly beyond said shoulders, and normally diverging tips to said end portions.

4. A cotter pin having tips normally separated but adapted to be brought together by compressing the pin intermediate its ends, outwardly projecting portions adjacent said tips, and shoulders adjacent said outwardly projecting portions whereby accidental dislodging of the cotter pin is prevented.

5. A cotter pin having a plurality of projecting portions adapted to engage successively with the edges of the hole in which the pin is located, and tips normally separated but adapted to be brought together by compressing the pin intermediate its ends.

6. A cotter pin having rearwardly projecting shoulders adapted to engage the edges of the hole in which the pin is located and end portions extending outwardly be- In testimony "whereof I have hereunto yond said shoulders. signed my name in the presence of the two' 7 A cotter pin having outwardly prosubscribed Witnesses. jecting portions adjacent the end of each of CHARLES J. WYMER. I 5 its arms and a tip extending from said por- Witnesses:

tion on each arm of said pin, the outer edges E. F. JONES, of said tips being normally diverging. PAUL CARPENTER. 

